I put my career first and baby-making second. By the time I reached 35, I was really worried that my fertility window was pretty small, if not closed all together, thanks to scary headlines. But here’s the thing: I had my kids at 37 and 39 without any reproductive help. So, I wondered: When it comes to your fertility, what’s the truth, and what’s a myth? Was I just lucky? Is a glass (or three) of wine really that bad? And what about men and their fertility issues? I talked to the experts to break down the truths and myths about fertility.

Truths

Smoking cigarettes increases your risk of being infertile. This is absolutely true — for both men and women, says Shahin Ghadir, MD, a reproductive endocrinologist and founding partner of the Southern California Reproductive Center, in Los Angeles. “Smoking has been shown in numerous research studies to affect both egg and sperm quality, as well as the function of the fallopian tubes,” he adds. So, if you’re still smoking, it’s time to kick the habit (seriously).

Drinking affects your hormones and thus your baby production. A glass here and there is okay, but binge drinking is definitely not. “Excessive drinking can affect the function of the liver, which in turn can affect the metabolism of hormones that are needed to promote healthy fertility and reproduction,” says Dr. Ghadir.

Almost 20 percent of U.S. moms have their first baby at age 35 or older. According to the Centers for Disease Control, more and more moms (like me) are waiting until their late 30s and early 40s to have a baby. So, if you’re in that category, you’re not flying solo.

Being overweight can affect your fertility. Yes — and this is true for both women and men. “For men, being overweight promotes higher levels of estrogen production, which in turn can reduce testosterone levels,” says Dr. Ghadir. “Additionally, when a man’s weight goes up, the testicles have a higher likelihood of staying in an overly heated environment between the thighs, and this excessive heat can affect sperm quality.” For women, being extremely overweight (or underweight, for that matter) can lead to hormonal imbalances, causing either excessive or reduced levels of the hormones needed for normal ovulation to occur.

Most couples are fertile. In fact, 85 percent of couples won’t have a problem getting pregnant, since only about 15 percent of all couples experience infertility. Think positive! Stress can play a role in infertility.

Myths

Infertility strikes more women than men. It’s time for us to stop taking the blame, because here’s the thing: Although most people, including women, think we are to blame, the truth is that 30 percent of all infertility issues can be traced to men, 30 percent can be traced to women, and the other 40 percent either involves both partners or is “unexplained” (meaning there’s no medical reason for the infertility).

Primary and secondary infertility levels are about the same. It’s surprising, but according to Alice D. Domar, PhD — associate professor of OBGYN and Reproductive Biology at Harvard Medical School and author of the book Conquering Infertility — research shows that secondary infertility is more common than primary infertility. “The reason may simply be that people are older when they have a second child,” she explains.

Having less sex is a good way to build up super sperm. This might seem true, but in reality, long periods of abstinence actually decrease the quality of the sperm. Plus, less sex means you’re less likely to have it at the right time of the month—during ovulation.

All lubricants are OK to use when you’re TTC. No, some commercial lubes, like KY jelly, can slow sperm down. “However, there are a few commercially available, sperm-friendly lubricants that can help keep intercourse comfortable when you’re trying to conceive,” says Dr. Ghadir. Talk to your doctor about which lubricants are okay to use.

Judy Koutsky is the former Editorial Director of KIWI magazine, a green parenting publication. She was also Executive Editor of Parenting.com, AOL Parent, and BabyTalk.com. Follow her on twitter @JudyKoutsky.